Bumblebees could fly over Mount Everest!

Bumblebees, with their chubby bodies and small wings, may not have a reputation for their aerial skills but scientists have found that the humble insect could scale Mount Everest - the highest mountain in the world.
Researchers captured six male bumblebees (Bombus impetuosus) in the wild in China and stuck them in a hyperbaric chamber, gradually sucking air out, to simulate higher elevation environments with reduced oxygen and air density.
They observed the bees' behaviour, recorded sound to calculate their wing beat rhythms, and analysed wing motion from video footage.
They found that the average bumblebee could still successfully hover at about 26,000 simulated feet, and two bees flew higher than 29,527 simulated feet - which is about 500 feet above the summit of Mount Everest, 'Smithsonian Magazine' reported.

"Much to our surprise, [bees] can fly much higher than we thought they would be able to," said Michael Dillon, an ecologist at the University of Wyoming in Laramie who worked with Robert Dudley, an ecologist at the University of California at Berkeley and the Smithsonian Tropical Research institute in Panama.
To reach such great heights, any flying organism (or even a helicopter) has two options: beat their wings faster or increase their wing stroke amplitude, the angle through which they beat their wings.

Just flapping their little wings faster would likely be harder for a bee because they beat their wings in a fairly unique way, so the best option for the bee is take wider strokes.

"They beat their wings through a wider arc so that each time they move their wings through that arc they're actually pushing their wings against more molecules than they would otherwise," Dillon said.
He noted that there are other more subtle changes to wing motions that could allow bees to increase the force that their wings produce as well.
The study was published in the journal Biology Letters.